// Copyright (c) 2022 Cesanta Software Limited // All rights reserved #include "mongoose.h" static const char *s_ssdp_url = "udp://239.255.255.250:1900"; static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) { MG_DEBUG(("%p got event: %d %p %p", c, ev, ev_data, fn_data)); if (ev == MG_EV_OPEN) { // c->is_hexdumping = 1; } else if (ev == MG_EV_RESOLVE) { // c->rem gets populated with multicast address. Store it in c->label memcpy(c->label, &c->rem, sizeof(c->rem)); } else if (ev == MG_EV_READ) { MG_INFO(("Got a response")); struct mg_http_message hm; if (mg_http_parse((const char *) c->recv.buf, c->recv.len, &hm) > 0) { size_t i, max = sizeof(hm.headers) / sizeof(hm.headers[0]); // Iterate over request headers for (i = 0; i < max && hm.headers[i].name.len > 0; i++) { struct mg_str *k = &hm.headers[i].name, *v = &hm.headers[i].value; if ((mg_vcasecmp(k, "SERVER") == 0) || (mg_vcasecmp(k, "LOCATION") == 0)) { printf("\t%.*s -> %.*s\n", (int) k->len, k->ptr, (int) v->len, v->ptr); } } printf("\n"); } // Each response to the SSDP socket will change c->rem. // We can now do mg_printf(c, "haha"); to respond back to the remote side. // But in our case, we should restore the multicast address in order // to have next search to go to the multicast address memcpy(&c->rem, c->label, sizeof(c->rem)); } } static void tfn(void *param) { struct mg_connection *c = param; if (c == NULL) return; MG_INFO(("Sending M-SEARCH")); mg_printf(c, "%s", "M-SEARCH * HTTP/1.1\r\n" "HOST: 239.255.255.250:1900\r\n" "MAN: \"ssdp:discover\"\r\n" "ST: urn:schemas-upnp-org:device:MediaRenderer:1\r\n" "MX: 5\r\n" "\r\n"); } int main(void) { struct mg_mgr mgr; static struct mg_connection *c; mg_mgr_init(&mgr); c = mg_connect(&mgr, s_ssdp_url, fn, NULL); mg_timer_add(&mgr, 2000, MG_TIMER_REPEAT | MG_TIMER_RUN_NOW, tfn, c); while (true) mg_mgr_poll(&mgr, 200); mg_mgr_free(&mgr); return 0; }